Just a simple fan for smaller motors. It's a very small script you can easily adapt in OpenScad, or you use the customizer.
The angles are 45° by default, so printing without support should be possible with most printers.

The axe hole will probably not fit, even if you measured correctly. The real size depends on the material used, the printing temperature and the printing speed. So, either experiment and adapt the variable "shrink" to your needs, or make the hole a bit too small and drill it to the correct size after printing.

Please note: Plastic can break and fast rotating blades can cause severe injuries e.g. to the eyes. Do not use such a fan without casing.